1. Field of the Invention
This invention relates to a panel structure of a display panel of the active matrix driving type, and particularly to a display panel, a display panel module and an electronic apparatus.
2. Description of the Related Art
At present, in the field of flat panel display (FPD) apparatus, a liquid crystal display apparatus (LCD) is the main current. However, the liquid crystal display apparatus which is not a self-luminous device requires a backlight, a polarizing plate and other members. Therefore, the liquid crystal display apparatus is disadvantageous in that it has a comparatively large thickness and is not necessarily sufficient in luminance.
On the other hand, an organic EL (electroluminescence) display apparatus which is one of self-luminous apparatus does not require a backlight or other members in principle. Therefore, it is considered that the organic EL display apparatus is more advantageous than the liquid crystal display apparatus in terms of reduction in thickness and assurance of high luminance.
Particularly in an organic EL display apparatus of the active matrix type wherein a switching element is formed for each pixel, the current consumption can be suppressed low by causing each pixel to hold light emission. Therefore, with an organic EL display apparatus of the type described, it is comparatively easy to achieve a large screen and high definition. From those reasons, the attention to the organic EL display apparatus is increasing in recent years.
FIG. 1 shows an example of a configuration in plan of an organic EL panel module. Referring to FIG. 1, the organic EL panel module 1 shown includes a glass substrate 3 having a display region 5 on which a plurality of pixel circuits ready for active driving are arranged in a matrix.
Scanning signal supply TABs 7, image signal supply TABs 9 and power supply TCPs 11 serving as leads are connected to different sides of an outer periphery of the display region 5. The wiring lines mentioned are connected to N pixel control lines, M image signal lines and so forth in the display region 5 through connection pads.
An organic film 13 is formed wider by approximately 1 to 2 mm than the outer edge of the display region 5. Further, a cathode film 15 is formed on the outer side of the organic film 13. An opposing glass plate 17 is mounted in such a positional relationship as seen in FIG. 1 after a sealing material not shown is applied.
FIG. 2 shows an enlarged plan view of the organic EL panel module 1 in the proximity of a frame of the glass substrate 3 and particularly shows a corner portion of the glass substrate 3 including a portion in the proximity of an outer edge of the opposing glass plate 17. A positioning mark 21 is used for relative positioning of the glass substrate 3 and the opposing glass plate 17. The opposing glass plate 17 can be mounted at a predetermined position of the glass substrate 3 by the use of the positioning mark 21.
A cathode power supply pad 23 and an anode power supply pad 25 correspond to the power supply TCPs 11. The cathode power supply pad 23 is used for supply of cathode power. The cathode power supply pad 23 is connected to a cathode common electrode through a contact portion 27.
The cathode common electrode is electrically connected to the cathode film 15 at an outer peripheral portion of the display region 5.
Meanwhile, the anode power supply pad 25 is used for supply of anode power. The anode power supply pad 25 is connected to the pixel circuits in the display region 5 through metal wiring lines formed on a lower layer of the cathode common electrode.
FIG. 3 shows a sectional configuration taken along line A-B of FIG. 2. Referring to FIG. 3, the sectional configuration of the organic EL panel module 1 is different between the inner side of the display region and the outer side of the display region.
For example, within the display region 5, a pixel circuit 31 formed from a thin film transistor and a holding capacitor is formed on the surface of the glass substrate 3, and a protective film 33 and a flattening film 35 are laminated as upper layers on the pixel circuit 31.
An organic EL thin film 37 formed from a metal anode electrode, an organic film and an organic cathode common electrode is laminated as an upper layer on the flattening film 35, and a sealing material 39 and the opposing glass plate 17 are laminated as upper layers on the organic EL thin film 37.
Meanwhile, in the outside region of the display region, that is, in a frame region of the glass substrate 3, the protective film 33, flattening film 35 and sealing material 39 are laminated in order on an upper face of the glass substrate 3.